"The Hound of the Baskervilles" by Sir Arthur Conan Doyle
Taking place in both London and Devon, the novel traces the story of American Sir Henry Baskerville, the heir to a considerable estate after the death of Sir Charles Baskerville of a heart attack.
Due to a West Country legend about a huge demon dog roaming the moors and seeking an ancient vengeance against the Baskervilles, locals are convinced that Sir Charles' death was no accident.
Sherlock Holmes is invited by a certain Dr. Mortimer to investigate the matter for the benefit of Sir Henry. Holmes and his sidekick Watson who is sent ahead to Devon are drawn into a fatal adventure of superstition and revenge on the barren, gloomy moors in this hugely enjoyable mystery.